diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 6380726f75389ff85519c0605e50d84a5fc0087f..9b7f3c4777302fca776eacc89a93bba4b11438eb 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -119,6 +119,10 @@ int libata_noacpi = 0;
 module_param_named(noacpi, libata_noacpi, int, 0444);
 MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in probe/suspend/resume when set");
 
+int libata_allow_tpm = 0;
+module_param_named(allow_tpm, libata_allow_tpm, int, 0444);
+MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands");
+
 MODULE_AUTHOR("Jeff Garzik");
 MODULE_DESCRIPTION("Library module for ATA devices");
 MODULE_LICENSE("GPL");
@@ -2161,8 +2165,14 @@ int ata_dev_configure(struct ata_device *dev)
 					       "supports DRM functions and may "
 					       "not be fully accessable.\n");
 			snprintf(revbuf, 7, "CFA");
-		} else
+		} else {
 			snprintf(revbuf, 7, "ATA-%d", ata_id_major_version(id));
+			/* Warn the user if the device has TPM extensions */
+			if (ata_id_has_tpm(id))
+				ata_dev_printk(dev, KERN_WARNING,
+					       "supports DRM functions and may "
+					       "not be fully accessable.\n");
+		}
 
 		dev->n_sectors = ata_id_n_sectors(id);
 
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 14daf4848f09add8d0e7e90659251fd25afcc649..f802dbce41aea02f186ad3828518bc173cc8e156 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2690,6 +2690,24 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
 	if ((tf->protocol = ata_scsi_map_proto(cdb[1])) == ATA_PROT_UNKNOWN)
 		goto invalid_fld;
 
+	/*
+	 * Filter TPM commands by default. These provide an
+	 * essentially uncontrolled encrypted "back door" between
+	 * applications and the disk. Set libata.allow_tpm=1 if you
+	 * have a real reason for wanting to use them. This ensures
+	 * that installed software cannot easily mess stuff up without
+	 * user intent. DVR type users will probably ship with this enabled
+	 * for movie content management.
+	 *
+	 * Note that for ATA8 we can issue a DCS change and DCS freeze lock
+	 * for this and should do in future but that it is not sufficient as
+	 * DCS is an optional feature set. Thus we also do the software filter
+	 * so that we comply with the TC consortium stated goal that the user
+	 * can turn off TC features of their system.
+	 */
+	if (tf->command >= 0x5C && tf->command <= 0x5F && !libata_allow_tpm)
+		goto invalid_fld;
+
 	/* We may not issue DMA commands if no DMA mode is set */
 	if (tf->protocol == ATA_PROT_DMA && dev->dma_mode == 0)
 		goto invalid_fld;
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index bbe59c2fd1e2210d7538e271398ee23465df7f19..048e26cfb339f62b87613af37baa3619962a00c3 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -60,6 +60,7 @@ extern int atapi_dmadir;
 extern int atapi_passthru16;
 extern int libata_fua;
 extern int libata_noacpi;
+extern int libata_allow_tpm;
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
 extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
 			   u64 block, u32 n_block, unsigned int tf_flags,
diff --git a/include/linux/ata.h b/include/linux/ata.h
index e672e80202a8f451c6ccd6b13808d926b4765dc0..3fbe6d7784abfc05f3ee5f8cecce66be2f28aae3 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -379,7 +379,6 @@ struct ata_taskfile {
 #define ata_id_has_ncq(id)	((id)[76] & (1 << 8))
 #define ata_id_queue_depth(id)	(((id)[75] & 0x1f) + 1)
 #define ata_id_removeable(id)	((id)[0] & (1 << 7))
-#define ata_id_has_dword_io(id)	((id)[48] & (1 << 0))
 #define ata_id_has_atapi_AN(id)	\
 	( (((id)[76] != 0x0000) && ((id)[76] != 0xffff)) && \
 	  ((id)[78] & (1 << 5)) )
@@ -415,6 +414,7 @@ static inline bool ata_id_has_dipm(const u16 *id)
 	return val & (1 << 3);
 }
 
+
 static inline int ata_id_has_fua(const u16 *id)
 {
 	if ((id[84] & 0xC000) != 0x4000)
@@ -519,6 +519,26 @@ static inline int ata_id_is_sata(const u16 *id)
 	return ata_id_major_version(id) >= 5 && id[93] == 0;
 }
 
+static inline int ata_id_has_tpm(const u16 *id)
+{
+	/* The TPM bits are only valid on ATA8 */
+	if (ata_id_major_version(id) < 8)
+		return 0;
+	if ((id[48] & 0xC000) != 0x4000)
+		return 0;
+	return id[48] & (1 << 0);
+}
+
+static inline int ata_id_has_dword_io(const u16 *id)
+{
+	/* ATA 8 reuses this flag for "trusted" computing */
+	if (ata_id_major_version(id) > 7)
+		return 0;
+	if (id[48] & (1 << 0))
+		return 1;
+	return 0;
+}
+
 static inline int ata_id_current_chs_valid(const u16 *id)
 {
 	/* For ATA-1 devices, if the INITIALIZE DEVICE PARAMETERS command